Indian Covid-19 variant spreading in the UK

One of the Indian coronavirus variants that’s been picked up in the UK is threatening to derail the roadmap for easing lockdown. As the Prime Minister Boris Johnson has highlighted, "it has been spreading",  and what’s got the government’s scientific advisory group - SAGE - worried is that this variant, which is known as “subtype 2” - or B 1.617.2 - is spreading within the community in the UK three times faster than other imported strains like the South Africa or Brazilian variants. This suggests it has some kind of enhanced transmissibility, which could strike out one of the government’s 4 tests that need to be fulfilled to proceed with re-opening the country. But, the quandary is that the total number of cases here is - at the moment - still relatively small, and the outbreaks have - so far - been confined mainly to specific parts of the country. So does this mean we’re off the hook? And how should we proceed? Christina Pagel is a mathematician at UCL and she’s been looking at the numbers…

Christina - There are two main sources of information. The first one is the UK COVID genetics consortium. They sequence positive samples from about half of the positive cases that we get to try and work out what variant each positive case is. They show that there are now been over 1,300 cases of the new variant of concern. The one that's called B1617.2. And it's basically been doubling every week since the end of March. There's another source called Sanger, the Wellcome Sanger Institute. And what they do is use the same data, but take out all travellers and take out search testing. So what they're trying to do is see how widespread is it in the community? And they're getting 500 cases in England in the community, also doubling every week

Chris - And distribution wise, where are these cases happening?

Christina - So they're concentrated at the moment in London and the Northwest, where Sanger estimates that about 20% of current cases there are this new variant and then also in the east of England where it's about 50% of cases. And there particularly it's Bedford and in the Northwest it's Bolton, Blackburn and Sefton.

Chris - And in terms of how well this variant can spread, because that's a critical question, isn't it? Because one argument the government have made in the past when considering variants is that they don't appear to have the same reproductive advantage that our existing strains of coronavirus do, and therefore they're unlikely to gain a toehold. How does this one weigh up against the dominant strain, the Kent variant we have in the UK at the moment?

Christina - Yeah, so you're absolutely right, but the other variants, they don't seem to have been able to compete against our Kent variant, which has been the most transmissible variance so far globally, but this new one, one of the reasons they made it a variant of concern is because it does seem to be at least as transmissible, as that's what Public Health England say, WHO today also made it a variant of concern globally, because they're worried about transmissibility. Because what's happened is that in India, it seems as if this new variant is outcompeting the Kent variant. So that kind of implies that it is fitter and we're seeing it gaining ground in England, also against our dominant Kent variant.

Chris - And are you comfortable, having looked at the numbers, that this is genuinely comparing apples with apples? Or is it because we're going after this variant and we're looking for it so we're skewing the data and making it look like it's spreading more.

Christina - I am worried because you're seeing very similar patterns in other countries and you are seeing that it is definitely increasing in the community in a way that the other variants haven't managed to do. So clearly there has been a difference between this variant and the other variants, which can't, I think be just explained by testing.

Chris - Do we have any insights into who is catching it? And specifically, is it people who have already tested positive for coronavirus? And where going with that is, one of the other questions we've seen emerging both in Brazil, in their outbreak, different variants admittedly, but also India, people appear to be being infected again with this new variant. Is there evidence that that's happening here?

Christina - So this is the million dollar question, at the moment there just isn't any evidence. There's a lot of anecdotal stories, but lots of them are from India, people getting reinfected or getting infected after one dose of vaccination. But we don't know what variant they'd been infected with because typically they don't sequence cases out there. The one thing we do know from Public Health England is that there was a care home that had an outbreak of this variant, the new variant where 14 residents got infected with COVID, some of whom had symptoms and some of whom went to hospital after two doses of AstraZeneca, but none of them were severely ill and all of them recovered. So that kind of, to me implies it is possible that maybe it can affect people easier. It's not proof

Chris - The government must be finding themselves in a difficult position, mustn't they? Because on the one hand they are announcing we're on track. We're doing well for reopening and easing many of the measures on the 17th of May and onward. Yet at the same time, one of the tests that have been set out to decide whether or not we should do that includes whether or not there are variants that are concerning us. So we're just on the cusp of opening things up again when we see this popping up on our radar and it seems to be something that's moving in a worrying direction.

Christina - Yeah. And it is difficult because tests one to three, based on vaccine roll out of vaccine to sufficiently end hospitalizations have all met, you know, that's all going really well. But to me, I personally don't think that the fourth test has been met. I think there are, there is now a variant that is concerning in its growth, but yeah, it's kind of, you know, do you think that the public health measures are enough to contain it? And if they are, then it probably is safe to open on Monday, but if they're not enough, then it probably isn't. And I don't know the answer to that. So I'm assuming that the government has confidence that the measures it has in place is enough to contain these outbreaks